Photochemical and thermal stabilization of polyamide fibre materials with tetra-methyl-piperidinyl substituted triazine

A process for the photochemical and thermal stabilisation of polyamide fibre materials, which comprises treating dyed or undyed polyamide fibre materials with water-soluble triazine derivatives of the general formula ##STR57## where R.sub.1 is a radical of the formula ##STR58## where R.sub.3 is hydrogen or oxyloxygen, hydroxyl, lower alkyl, lower alkenyl, lower alkoxy, acyl or benzyl and Z is --O-- or --(NR.sub.4)--, where R.sub.4 is hydrogen or lower alkyl, R.sub.2 is hydrogen, halogen, lower alkyl, lower alkoxy, acylamino, carboxyl, an unsubstituted or halogen- or (lower alkyl)-substituted phenylsulfo, phenoxy, phenylthio or styryl radical or --SO.sub.3 M, Q is --O-- or --(NR.sub.4)--, R is halogen, lower alkyl, lower alkoxy, phenyl(lower alkoxy), cycloalkoxy, (lower alkyl)thio, phenyl(lower alkyl)thio, cycloalkylthio, mono(lower alkyl)amino, di(lower alkyl)amino, phenyl(lower alkyl)amino, cycloalkylamino, phenoxy, phenylamino, phenylthio, phenyl, 1-azacycloalkyl, morpholino, R.sub.1 or a radical of the formula ##STR59## where M is hydrogen, an alkali metal, an alkaline earth metal, ammonium or an organic ammonium radical, and Q is as defined for the formula (1), the compounds of the formula (1) having not more than 2 --SO.sub.3 M substituents.